High efficiency stove

ABSTRACT

A high efficiency stove has a chamber attached to a base. The chamber is liquid tight and holds liquid fuel such as alcohol within. At least one heat conductor is provided to capture heat and redirect it back into the fuel to increase the gasification process required for combustion. This heat is normally lost in conventional stoves. This greatly increases the efficiency of the stove and allows small size stoves to have a heat output superior to conventional stoves. In one embodiment, removable heat conductors are used to adjust heat output. In another embodiment an adjustment sleeve is used that effectively changes the height of the chamber to adjust output. Another embodiment utilizes an outer sleeve that rotates to open and close at least one airflow opening provided for that purpose. One embodiment includes cooking support legs that allows a user to use a pot or pan.

RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No. 12/793,713 filed Jun. 4, 2010, and entitled “High Efficiency Stove.”

BACKGROUND OF THE INVENTION

The ability to control fire and use it for heating, cooking, metal working, etc. has led to a complete change in the way humans live and the fire revolution is not really over. Without control over fire, modern life would not be possible.

Open air campfire type fires were the most prevalent kind of controlled fire in our early history. Eventually, our ancestors learned to bring the open air fire inside their dwellings to heat and cook while sheltered from the environment. Indoor fires were basically fire pits with a way to vent the smoke and gasses produced, but eventually true stoves were invented that enclosed the fire and more evenly distributed the heat produced and were safer to operate. Benjamin Franklin invented a stove that greatly improved the efficiency and helped many people to be more comfortable and make more efficient use of fire.

The first portable stove was invented in the 19^(th) century and used kerosene as the fuel. A stove that used alcohol was known in the early 1900's. Although technology has rapidly progressed since then, the basic alcohol stove has not changed very much since then. There is a need for an efficient, simple to operate alcohol stove that is portable and easy to transport and set up and safe to use.

SUMMARY OF THE INVENTION

A high efficiency stove has a chamber attached to a base. The chamber is liquid tight and holds liquid fuel such as alcohol within. At least one heat conductor is provided to capture heat and redirect it back into the fuel to increase the gasification process required for combustion. This heat is normally lost in conventional stoves. This greatly increases the efficiency of the stove and allows small size stoves to have a heat output superior to conventional stoves. In one embodiment, removable heat conductors are used to adjust heat output. In another embodiment an adjustment sleeve is used that effectively changes the height of the chamber to adjust output. Another embodiment utilizes an outer sleeve that rotates to open and close at least one airflow opening provided for that purpose. One embodiment includes cooking support legs that allows a user to use a pot or pan.

Other features and advantages of the instant invention will become apparent from the following description of the invention which refers to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cutaway view of a high efficiency stove according to an embodiment of the present invention.

FIG. 2 is a cutaway view of the high efficiency stove shown in FIG. 1 with additional heat conductor added.

FIG. 3 is a cutaway view of the high efficiency stove shown in FIG. 2 with another heat conductor added.

FIG. 4 is a cutaway view of the high efficiency stove shown in FIG. 3 showing the location of adjusting sleeve in another position.

FIG. 5 is a cutaway view of the high efficiency stove shown in FIG. 3 showing the location of adjusting sleeve in another position.

FIG. 6 is a perspective view of a high efficiency stove according to an embodiment of the present invention.

FIG. 7 is a top view of the high efficiency stove shown in FIG. 6.

FIG. 8 is a top view of the high efficiency stove shown in FIG. 6 with additional heat conductors in place.

FIG. 9 is a perspective view of a high efficiency stove shown in FIG. 6 with the addition of a starting primer tray.

FIG. 10 is a perspective view of the high efficiency stove shown in FIG. 9 with the addition of cooking support legs.

FIG. 11 is a perspective view of a high efficiency stove shown in FIG. 6 with alternative heat conductors installed.

FIG. 12 is a cutaway view of a small high efficiency stove according to an embodiment of the present invention.

FIG. 13 is a cutaway view of the small high efficiency stove shown in FIG. 12 with additional heat conductors.

FIG. 14 is a cutaway view of the high efficiency stove shown in FIG. 6.

FIG. 15 is a perspective view of a high efficiency stove according to an embodiment of the present invention.

FIG. 16 is a perspective view of a high efficiency stove shown in FIG. 6 with alternative heat conductors installed.

FIG. 17 is a top view of the high efficiency stove shown in FIG. 9 with alternative heat conductors in place.

FIG. 18 is a cutaway view of the high efficiency stove shown in FIG. 16.

FIG. 19 is a cutaway view of a high efficiency stove according to an embodiment of the invention.

FIG. 20 is a perspective view of the high efficiency stove shown in FIG. 19.

FIG. 21 is a perspective view of the high efficiency stove shown in FIG. 9 with the addition of cooking support legs.

FIG. 22 a cutaway view of a high efficiency stove according to an embodiment of the invention.

FIG. 23 is a perspective view of a high efficiency stove according to an embodiment of the invention.

FIG. 24 is a perspective view of the high efficiency stove shown in FIG. 23 with the addition of cooking support legs.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description of the invention, reference is made to the drawings in which reference numerals refer to like elements, and which are intended to show by way of illustration specific embodiments in which the invention may be practiced. It is understood that other embodiments may be utilized and that structural changes may be made without departing from the scope and spirit of the invention.

Referring to FIGS. 1 through 5, a high efficiency stove 100 is shown having a base 140 with a chamber 110 attached to an upper surface. The joint between chamber 110 and base 140 is liquid tight. This may be obtained by welding, soldering or gluing chamber 110 to base 140 or by manufacturing chamber 110 with a bottom portion integrally formed therein and then attached to base 140.

A heat conductor 120 is provided to add to the thermal conductivity of the stove. A plurality of heat conductors 120 may be used to further enhance the heat output of stove 100. In use, the operator may add or subtract heat conductors 120 as desired to obtain the best result. Liquid fuel 130 is added to chamber 110 and then ignited. As fuel 130 burns, heat conductors 120 heat up and enhance the transformation of liquid fuel 130 to a gaseous state needed for combustion. As additional heat conductors 120 are added, the heat output of stove 100 is increased since heat conductors 120 redirect the heat back into fuel 130 which increases the gasification of fuel 130 which is required for combustion.

This heat is normally lost to the environment in conventional stoves. Heat conductors 120 are made of copper which has a high thermal conductivity. Heat conductors 120, once heated, require little heat to maintain their temperature, thus increasing stove 100 efficiency. Of course other high thermally conductive materials such as aluminum may be used without departing from the present invention as long as their melting temperature is sufficiently high.

To adjust the heat output of stove 100, the user slides an adjusting sleeve 115 up to slow down the output and down to increase the heat produced with intermediate outputs corresponding to the height selected. Heat conductors 120 are permanently mounted within base 140. Liquid fuel 130 is alcohol although other similar fuels may be used.

Adjusting sleeve 115 is provided to slide up and down over chamber 110 to effectively adjust the height of stove 100. The height adjustment controls the heat output of stove 100 by controlling the exposure of heat conductors 120 to the surrounding air and the amount of air available for combustion. FIG. 4 is illustrative of a maximum output position with FIG. 5 showing a minimum output position. Additionally, a stop or series of stops may be used to provide preselected air adjustment settings. This allows a user to easily select the energy output.

Referring now to FIGS. 6, 7 and 8, a high efficiency stove 600 is shown having a base 640 which is basically conical in shape to stabilize stove 600. A chamber 610 is provided to hold liquid fuel (not shown) such as alcohol. An inner sleeve 620 is provided to rotatably allow a user to adjust the airflow reaching the fuel. At least one air adjustment opening 650 is disposed within a wall of chamber 610 and in inner sleeve 620. When these openings 650 line up, maximum airflow is provided. To close off airflow, inner sleeve 620 is rotated to close off airflow. In this manner any position between maximum and closed off may be selected to provide fine control. Of course it is possible to provide an outer sleeve that rotates around a fixed inner chamber without departing from the present invention.

A plurality of air flow openings 650 may be provided to further enhance the control a user has over the combustion within chamber 610. Airflow openings 650 may be provided in pairs, three, four, five or more limited by the amount of space present along the wall of chamber 610 and structural considerations. As inner sleeve 620 is rotated, all openings are adjusted in unison to control the flow of air.

As shown in FIGS. 7 and 8 and 14, heat conductors 630 may be arranged in many different patterns. A heat conductor holder 645 is provided to hold heat conductors 630. Heat conductors 630 may be permanently joined by being welded, soldered or glued to holder 645 or may be friction fitted to allow a user to add or remove them. A plurality of heat conductors 630 are used to increase the heat output, but of course, there must be room for combustion to take place so there is an upper limit to the number of heat conductors 630 used which mostly depends on the diameter of chamber 610.

As shown in FIG. 9, a primer tray 680 is provided to aid in starting high efficiency stove 600. Primer tray 680 wraps around chamber 610 close to airflow openings 650. A flammable fluid such as alcohol is added to primer tray 680 and chamber is filled close to the bottom of airflow openings 650. The fluid in primer tray 680 is ignited and this provides fire and sufficient temperature to bring high efficiency stove 600 up to optimal operating temperature. Once stove 600 reaches optimal temperature, no more fluid need be added to primer tray 680 during use.

Referring now to FIG. 11, high efficiency stove 600 is shown having a plurality of heat conductors 632 having a curved upper portion to allow a user to remove them. In this embodiment, heat conductors 632 are not permanently installed and are friction fitted to holes provided in a bottom portion of base 640. Of course other geometries are usable as well.

Now referring to FIGS. 12 and 13, a small scale high efficiency stove 200 is shown having a chamber 210 attached to a base 240. The seam between chamber 210 and base 240 is liquid tight to hold liquid fuel 130 therein. At least one heat conductor 120 is provided to increase the heat output as discussed above. A plurality of heat conductors are used as shown in FIG. 13. The user may add or subtract heat conductors 120 as desired. Heat conductors 120 simply rest within chamber 210 without the need for further support. This embodiment is generally usable for small diameter stoves of 1½ inch diameter or less. Fuel 130 may be filled almost to the height of chamber 210. All heat conductors 120 may be removed and a lid placed over stove 200 to extinguish.

Referring to FIG. 15, a large scale high efficiency stove 300 is shown having a chamber 310 attached to a base 340. Again as discussed above, liquid fuel is contained within chamber 310. A plurality of sleeves 325 are provided to hold heat conductors 120. In use, one leg of u-shaped heat conductor 120 is slipped within sleeve 325 and the other leg is unsupported resting within chamber 310. Liquid fuel is added and ignited thus heating heat conductors 120 which accelerates the burning of the fuel. The user may add or remove heat conductors as desired. Of course, once ignited, pliers or other tool must be used to remove or add heat conductors.

Referring now to FIGS. 16, 17 and 18, high efficiency stove 600 is shown having u-shaped heat conductors 634 permanently mounted within heat conductor holder 645. Again as discussed above, heat conductors may be welded, soldered or glued. This configuration maximizes the exposed surface area of heat conductors 634 by exposing a top portion of heat conductor to the flame once liquid fuel is ignited.

Now referring to FIG. 10, high efficiency stove 600 is equipped with leg sleeves 685 that removably hold cooking support legs 690. When cooking support legs 690 are inserted in leg sleeves 685, a platform for holding a cooking pot or pan 695 is provided that allows a user to place pot or pan 695 over high efficiency stove 600. When being stored, the legs 690 are simply removed and stack compactly for easy storage allowing the unit to fit within a backpack or other small storage space. Leg sleeves 685 are attached along a bottom portion of base 640 and along an outer portion of primer tray 680 to provide a very secure and stable base for cooking pot or pan 695.

Now referring to FIGS. 19 and 20, a high efficiency stove 700 is shown having a chamber 720 and a moveable outer sleeve 710. A heat conductor holder 745 is attached to a base portion of chamber 720 and holds heat conductors 634 therein. Heat conductors 634 are u-shaped but other shapes can be used such as simple rods or other shapes as shown in FIG. 22. Chamber 720 holds fuel 130. In use, fuel 130 is added until reaching just below an air adjustment opening 750. Outer sleeve 710 is rotatable and may have one or more openings 750 as discussed above. In this embodiment, corresponding openings 750 are disposed in chamber 720 and outer sleeve 710 is rotated to provide maximum air flow and off. Outer sleeve 710 may be infinitely rotatable or may be provided with preset settings. Additionally, a stop or limiting stop may be used to limit how far outer sleeve 710 can rotate.

A primer tray 780 wraps around a portion of chamber 720 and is disposed just below air adjustment opening 750. A flammable fluid such as alcohol is added to primer tray 780 and ignited. This flame ignites fluid 130 within chamber 720 and also helps direct warm air in and through air adjustment opening 750 which encourages a convection air flow to begin thereby increasing the efficiency of stove 700.

Referring now to FIG. 21, high efficiency stove 700 is equipped with leg sleeves 685 that removably hold cooking support legs 790. When cooking support legs 790 are inserted in leg sleeves 685, a platform for holding a cooking pot or pan 695 is provided that allows a user to place pot or pan 695 over high efficiency stove 700. When being stored, the legs 790 are simply removed and stack compactly for easy storage allowing the unit to fit within a backpack or other small storage space as discussed above. Leg sleeves 685 are attached along a bottom portion of base 740 and along an outer portion of primer tray 780 to provide a very secure and stable base for cooking pot or pan 695.

Now referring to FIG. 22, high efficiency stove 200 is shown having a center support 145 attached to base 240. Chamber 210 holds alcohol 130 and a shaped heat conductor 122. Of course other shapes such as circles, triangles, etc. may be used. It is also possible to operate stove 200 without center support 145 by simply inserting shaped heat conductor 122 within chamber 210.

Referring now to FIG. 23, a high efficiency stove 800 is shown having a chamber 740 that holds alcohol. Plurality of sleeves 325 are provided to hold heat conductors 120 as shown in FIG. 15. In use, one leg of u-shaped heat conductor 120 is inserted within sleeve 325 and the other leg is unsupported resting within chamber 310. Primer tray 780 wraps around a portion of chamber 740 and aids in starting stove 800. The user may add or remove heat conductors as desired.

Now referring to FIGS. 23 and 24, high efficiency stove 800 has leg support 785 attached to a portion of chamber 740 and primer tray 780 to support cooking legs 790 as discussed above with respect to FIG. 21. Again, other shaped legs may be used without departing from the spirit of the invention.

Although the instant invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. 

1. A high efficiency stove comprises: a base; a chamber defining a fuel containing portion adapted to hold fuel; said chamber having a bottom edge; said bottom edge being joined to an upper portion of said base wherein said fuel containing portion is sealed to prevent leakage of said fuel; and at least one heat conductor adapted to fit within said chamber.
 2. The high efficiency stove of claim 1 wherein said at least one heat conductor is adapted to transfer heat from a flame to said fuel.
 3. The high efficiency stove of claim 2 wherein the amount of heat transferred by said at least one heat conductor is adjustable by a user.
 4. The high efficiency stove of claim 1 wherein said at least one heat conductor is adapted to extend past an upper edge of said chamber.
 5. The high efficiency stove of claim 1 wherein said at least one heat conductor is removable.
 6. The high efficiency stove of claim 1 further comprising an adjusting sleeve telescopically fitting over said chamber wherein said adjusting sleeve effectively changes the height of said chamber.
 7. The high efficiency stove of claim 6 wherein said at least one heat conductor is permanently affixed to said base.
 8. The high efficiency stove of claim 6 wherein said adjusting sleeve is adapted to selectively move between a maximum position which is at least as high as a top of said at least one heat conductor and a minimum position which is generally the same height as an upper edge of said chamber.
 9. The high efficiency stove of claim 1 further comprising: an outer sleeve concentrically disposed over said chamber wherein said outer sleeve is rotatable; and at least one air adjustment opening in a side portion of said chamber and a corresponding side portion of said outer sleeve whereby said outer sleeve is rotatably adjustable between a maximum airflow position and a no airflow position.
 10. The high efficiency stove of claim 9 further comprising a primer tray disposed around an outer portion of said chamber wherein a flammable fluid is held therein.
 11. The high efficiency stove of claim 10 further comprising at least three cooking leg supports removeably attached to said base wherein said cooking leg supports are adapted to support a cooking pan over said high efficiency stove.
 12. The high efficiency stove of claim 9 wherein said at least one heat conductor is substantially straight with a curved end whereby insertion and removal is enhanced.
 13. The high efficiency stove of claim 1 further comprising at least one heat conductor sleeve disposed on an inner surface of said chamber whereby said at least one heat conductor sleeve is adapted to provide support for said at least one heat conductor.
 14. The high efficiency stove of claim 10 wherein said at least one heat conductor is generally u-shaped.
 15. The high efficiency stove of claim 1 wherein said chamber is adapted to contain a liquid fuel.
 16. The high efficiency stove of claim 15 wherein said liquid fuel is alcohol.
 17. The high efficiency stove of claim 1 further comprising a generally central support disposed on a bottom portion of said chamber wherein a portion of said at least one heat conductor is adapted to fit within said central support.
 18. The high efficiency stove of claim 17 wherein said at least one heat conductor is generally m-shaped.
 19. The high efficiency stove of claim 1 wherein said at least one heat conductor is made of aluminum.
 20. The high efficiency stove of claim 1 wherein said at least one heat conductor is made of copper.
 21. The high efficiency stove of claim 9 wherein said outer sleeve is adapted to selectively move between a maximum position and a minimum position. 